1. Technical Field
This disclosure relates generally to projectors for eye-mounted displays.
2. Description of Related Art
An eye-mounted display has been proposed by Deering. See, e.g. U.S. Pat. No. 8,786,675, “Systems using eye mounted displays.” One type of eye-mounted display is based on a tiny projector mounted inside a contact lens. The projector projects images onto the retina of a person wearing the contact lens. The projector must be very small to fit in the contact lens, so small that, for convenience, Deering called it a “femtoprojector”. A typical femtoprojector preferably is no larger than about one or two millimeters in any dimension.
Eye-mounted displays can be used for virtual reality applications and also for augmented reality applications. In virtual reality applications, the images projected by the eye-mounted display replace what the user would normally see as his external environment. In augmented reality applications, the images projected by the eye-mounted display augment what the user would normally see as his external environment, for example they may appear as additions to the external environment.
The femtoprojectors in an eye-mounted display include an image source and an optical system. A femtoprojector's optical system is designed to project images from the image source onto the retina so that the images appear in a person's field of vision. The femtoprojector optical systems are constrained to fit inside a contact lens while also providing appropriate magnification and sufficient image quality.
The figures depict various embodiments for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles described herein.